Introduced support for the new SPI IP (SPISG). The SPISG is
a communication-oriented SPI controller from Amlogic,supporting
three operation modes: PIO, block DMA, and scatter-gather DMA.

Add the drivers and device tree bindings corresponding to the SPISG.

Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
Changes in v2:
- Use regmap to operation register and drop bitfied define.
- Use "SPISG" prefix intead of "SPICC", and declare clock div table in the spisg_device. 
- Delete other power operation functions except for runtime_supspend and runtime_resume.
- Fix some format corrections.
- Link to v1: https://lore.kernel.org/r/20250604-spisg-v1-0-5893dbe9d953@amlogic.com (local)

---
Sunny Luo (2):
      dt-bindings: spi: Add binding document of Amlogic SPISG controller
      spi: Add Amlogic SPISG driver

Xianwei Zhao (1):
      MAINTAINERS: Add an entry for Amlogic spi driver

 .../devicetree/bindings/spi/amlogic,a4-spisg.yaml  |  55 ++
 MAINTAINERS                                        |   9 +
 drivers/spi/Kconfig                                |   9 +
 drivers/spi/Makefile                               |   1 +
 drivers/spi/spi-amlogic-spisg.c                    | 878 +++++++++++++++++++++
 5 files changed, 952 insertions(+)
---
base-commit: bd30b995df8fd053e13d10f78dbc7b2fa5ed1aae
change-id: 20250603-spisg-78f21682ebac

Best regards,
-- 
Xianwei Zhao [off-list ref]